Century Optics .3X Ultra Fisheye HD Z7U/S270U Adapter Bayonet Mount

The Century Optics .3x Ultra Fisheye gets you the widest view possible, with extreme barrel distortion. This non-zoom-thru add-on provides a 130-degree horizontal angle of view. The fisheye exaggerates depth, pulling nearby objects closer and causing distant objects to recede into the background.

A fixed adapter, the Fisheye doesn't allow for zooming - but you'll want to stay at the wide end of the range anyway, for the most pronounced effect. It comes in the popular Bayonet Mount that attaches with a twist to the front of the lens.